THE INFLUENCE OF PRENATAL X‐IRRADIATION ON THE ACTIVITY OF sRNA‐AMTNOACYL SYNTHETASES IN THE DEVELOPING RABBIT BRAIN

Abstract

—The activities of sRNA‐aminoacyl synthetases (EC 6.1.1) were investigated in the cerebral white and grey matter of rabbits subjected during their prenatal life to a single X‐ray dose of 150 rad. The results of investigations have shown that ionizing radiation acting during intrauterine development of the experimental animal brings about a distinct depression of all sRNA‐aminoacyl synthetase activities in the newborn irradiated litter. During the postnatal development of these animals the activities of some of the synthetases further decreased and even at adulthood, where they are normally very low, their activities were below the control values. The activities of some other synthetases, after the initial depression, showed no further decrease and at adulthood had values comparable to controls. Our results indicate clearly that prenatal exposure to ionizing radiation also affects the step of protein biosynthesis which depends on the activity of sRNA‐aminoacyl synthetases.